CN105004162A - Waste heat recovery type steam plate-press dryer - Google Patents

Abstract

The invention discloses a waste heat recovery type steam plate-press dryer. A dryer body is provided with a driving wheel, a driven wheel and a scratch board; the scratch board is used for driving materials to be conveyed on a steam flat plate; an upper drying area is tangentially connected with a cyclone dust removal waste heat efficient recoverer formed by stacking a tube type heat exchanger and a cyclone dust removal device through an induced draft fan; the upper end of a shell pass of the tube type heat exchanger is connected with an air inlet pipe; the lower end of the shell pass of the tube type heat exchanger is connected with a lower drying area through an air blower; an impeller of the induced draft fan is provided with blades taking the shape of a hollow reversed water drop; the shape contour of the induced draft fan is involute. The waste heat recovery type steam plate-press dryer has the advantages that waste heat recovery and dust removal are integrated creatively, and the cyclone dust removal waste heat efficient recoverer is designed, so that waste heat recovery and dust removal are completed in one step, the equipment investment is reduced, and the working efficiency is improved; the blades adopt the hollow reversed water drop structures, so that real-time cleaning of dust is achieved, and the impeller strength of the induced draft fan is improved, the stability is enhanced, and safety accidents caused by dust accumulation are effectively eliminated; therefore, the application prospect is wide.

Description

Tail heat recovery steam plate dryer

technical field

The invention relates to a dryer, in particular to a tail heat recovery type steam plate dryer which does not accumulate dust in a fan.

Background technique

Due to its mature technology, strong adaptability, low energy consumption and high reliability, the steam heating plate dryer has become one of the main preferred equipment for drying materials. The material is conveyed by scraper on the steam heating plate for contact heating drying. Due to the simple structure, extremely low energy consumption, strong processing capacity, and each layer of material is turned over, the quality of the dried product is particularly uniform and reliable. However, the drying process needs to continuously discharge hot and humid tail gas to promote the drying process. Since the exhaust gas is rich in a large amount of tail heat, it is necessary to perform tail heat recovery operation on the tail gas, so it is of great significance to optimize the design of tail heat recovery.

The induced draft fan is the key equipment for dehumidification of the steam flat plate dryer. The induced draft fan is generally a centrifugal fan. The continuous, stable and reliable operation of the induced draft fan is very important for the dehumidification of the dryer. Because most of the occasions where the dryer is used contain a certain amount of dust, When the induced draft fan is working, when the air flow passes through the high-speed rotating fan impeller, due to the centrifugal separation, the dust particles will separate from the air flow phase and deposit on the fan impeller.

Since the impeller speed of the induced draft fan is generally high, as long as there is a small amount of dust in the airflow, more dust will accumulate after a long time of work, thereby changing the balance of the impeller rotation of the induced draft fan. , it will accumulate more and gradually change the static and dynamic balance of the induced draft fan impeller, resulting in vibration. Once the partly hardened dust is shaken off, it will immediately leave the dynamic rotation balance of the induced draft fan, and then generate strong vibration, which may cause serious personnel and equipment safety accidents.

Therefore, if a centrifugal induced draft fan impeller can be designed so that it can be cleaned automatically, there is no need to worry about dust accumulation, which is of great significance for maintaining the stable and reliable operation of the induced draft fan and preventing safety accidents.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a tail heat recovery steam flat plate dryer with a simple and practical structure that can automatically clean the dust on the impeller of the induced draft fan.

In order to overcome the deficiencies in the prior art, the present invention takes the following technical solutions:

A tail heat recovery steam plate dryer, including a dryer and an induced draft fan, characterized in that the dryer is equipped with a driving wheel, a passive wheel and a scraper to drive materials to be transported on the steam plate, and the steam plate is connected to a steam valve and a steam trap There is a middle partition in the dryer to divide the drying area into an upper drying area and a lower drying area; the upper drying area is tangentially connected by an induced draft fan, and the cyclone dedusting tail heat is efficiently recovered by stacking a tube-and-tube heat exchanger and a cyclone dust collector. After the swirl dust removal, the dust is discharged through the air lock at the bottom of the cone. The tail gas is connected to the cone through the swirl rising pipe, dispersed evenly, and then passes through the tubes. It is concentrated by the upper cone bucket and then discharged from the exhaust pipe; The upper end of the shell side of the heater is connected to the air intake pipe, and the lower end is connected to the lower drying area through the blower; the induced draft fan includes a fan impeller and a casing, and the fan impeller includes an impeller back plate, an impeller panel and blades, and the blades are arranged radially to the impeller axis and symmetrical to the center The hollow anti-drop shape; the hollow anti-drop-shaped blade is connected to the impeller panel and welded with the impeller back plate to form the main body of the impeller; the impeller panel is provided with an air inlet, the impeller back plate is fixed by rivets and connected to the shaft seat, and the shaft seat is connected to the fan shaft through the shaft hole. The casing is equipped with an air inlet and an air outlet. The outline of the casing is an involute, and the center of the involute circle coincides with the axis of the fan. The involute starts from the inside of the air outlet of the casing. The involute circle gradually increases and ends at the outer side of the air outlet of the casing. The width of the air outlet of the casing is equal to the circumference of the involute circle; coincides with the impeller axis.

The steam trap is connected tangentially to the cyclone dust collector, and the steam condensed water with high temperature is used to spray the cyclone dust collector, so as to realize the effective utilization of waste heat and waste water.

The dryer is equipped with a feed hopper and a discharge hopper to realize continuous feed drying.

The hollow anti-drop-shaped blade is welded and combined by two curved metals, and has a symmetrical streamlined shape.

The casing is fixed on the base. The casing acts as a seal, and the intake air at the air inlet obtains kinetic energy through the rotation of the impeller, and the energy is converted in the casing, and a part of the kinetic energy is converted into the static pressure energy of the gas, so that the output airflow has a velocity dynamic pressure head and a static pressure head , the sum of the two is the total pressure of the fan.

The air inlet of the casing can be connected to the air duct as required, and the cover plate of the air inlet is detachable, and is connected to the casing by bolts. The volute-shaped involute profile of the casing meets the needs of airtight fan casing and efficient energy conversion while transporting gas. , so that the output airflow can reach the required flow rate and full pressure.

The casing air inlet cover plate is fixedly connected to the casing by bolts and can be disassembled.

When the equipment is working, the steam plate heats and dries the material in a contact manner, generating more wet and hot water vapor, and the induced draft fan tangentially introduces the wet and hot water vapor in the dryer into the cavity between the tube-and-tube heat exchanger and the cyclone dust collector. Realize cyclone dust removal and the first step of cyclone heating for the fresh air entering the shell side of the heat exchanger, and the dust is output by the air locker.

The wet hot water vapor after dedusting enters the tube side of the heat exchanger through the swirl riser tube, and finally is discharged from the exhaust pipe. The wet hot water vapor heats the fresh air entering the shell side in the second step in the tube side. The blower blows into the lower drying area for gas replacement drying. The air flow in the lower drying area passes through the material from left to right, and the air flow turns back from the end of the middle partition, and then passes through the upper drying area from right to left, so there is sufficient Time and path for efficient drying of materials.

When the induced draft fan impeller of the present invention is used, because the blades are designed to be hollow and anti-waterdrop-shaped, and the blade shafts are radially and center-symmetrical, when rotating at high speed, the surface of the blades has a centrifugal self-cleaning effect under the centrifugal force, so that the dust cannot be attached due to the centrifugal force , so that it will not affect the dynamic and static balance of the impeller, and will not accumulate dust; the technical solution of this blade structure is especially suitable for the wide-impeller induced draft fan with large air flow.

Compared with prior art, the beneficial effect of the present invention also lies in:

Creatively integrate tail heat recovery and dust removal, and design a high-efficiency tail heat recovery device for cyclone dust removal, so that tail heat recovery and dust removal can be completed in one step, reducing equipment investment and improving work efficiency; The swirling flow and the hot and humid steam in the heat exchanger tubes rise to perform two-step high-efficiency heat exchange and tail heat recovery. The efficiency is extremely high, and the tail heat is fully utilized; the cyclone dust collector is sprayed with high-temperature steam condensed water , to realize the effective utilization of waste heat and waste water.

The blades are designed to be hollow and drop-shaped, and the blade axis is radially and center-symmetrical, so that the fan backboard and the panel connected to it can resist relative torsion and have strong extrusion rigidity, which can prevent the root of the fan blade from connecting to the backplane caused by long-term use. fracture.

The blades are designed to be hollow and anti-droplet-shaped, and the blade axis is radially and center-symmetrical. Even if the fan impeller is made of thinner plates, it can obtain higher strength, ensure stable and reliable use, save materials, and be easy to manufacture. Conducive to light and small equipment.

The hollow anti-drop-shaped blade has a streamlined shape, and the airflow of the blade is smooth and sweeping, so the fan running noise is particularly small, which improves the working environment.

The invention ingeniously designs the blade of the induced draft fan into a hollow anti-water drop shape, and the shape of the blade axis is radially and center-symmetrical, which realizes the real-time cleaning of dust on the blade, prolongs the service life of the equipment and can effectively prevent safety accidents caused by dust accumulation. The application prospect is broad.

Description of drawings

Fig. 1 is the plane structure schematic diagram of the present invention

Fig. 2 is a schematic plan view of the impeller of the induced draft fan.

Fig. 3 is a schematic cross-sectional structure diagram of an induced draft fan impeller.

Fig. 4 is a schematic plan view of the induced draft fan.

Each label in the figure means:

A. Induced fan; C and D are the whereabouts of materials; 1. Cyclone dust collector; 2. Tangential inlet; 3. Exhaust pipe; 4. Tube-and-tube heat exchanger; Rising pipe; 7. Air locker; 8. Drain valve; 9. Air intake pipe; 10. Steam heating plate; 11. Blower; 12. Steam valve; 13. Feeding hopper; 14. Upper plate of the chassis; 15. Lower chassis Plate; 16, the middle partition of the chassis; 31, the reverse drop-shaped blade; 32, the outer circle of the impeller; 33, the air inlet of the impeller; 34, the shaft seat; 35, the rivet; 36, the shaft hole; 37, the back plate of the impeller; 38, Impeller panel; 41, impeller; 42, casing air inlet; 43, involute circle; 44, frame; 45, casing; 46, casing air inlet cover; 47, casing air outlet; B, machine Shell air outlet width.

Detailed ways

Now in conjunction with accompanying drawing, the present invention is described in further detail.

As shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, the tail heat recovery type steam plate dryer includes a dryer and an induced draft fan A, and the dryer is equipped with a driving wheel, a driven wheel and a scraper to drive materials on the steam plate 10 Conveying, the steam plate 10 is connected to the steam valve 12 and the steam trap 8; there is a middle partition 16 in the dryer to divide the drying area into an upper drying area and a lower drying area; The high-efficiency cyclone tail heat recovery device formed by superimposing the cyclone dust collector 4 and the cyclone dust collector 1. After the cyclone dust removal, the dust is discharged through the air locker 7 at the bottom of the cone. The tubes 5 are discharged from the exhaust pipe 3 after being concentrated by the upper cone bucket; the upper end of the tube-and-tube heat exchanger 4 is connected to the intake pipe 9, and the lower end is connected to the lower drying area through the blower 11; the induced draft fan includes fan impeller 41 and The casing 45 and the fan impeller 41 include an impeller back plate 37, an impeller panel 38 and blades 31, and the blades 31 are arranged in a hollow anti-drop shape that is radial to the impeller axis and symmetrical to the center; the hollow anti-drop shape blade 31 is connected to the impeller panel 38 and connected to the impeller The back plate 37 is welded to form the main body of the impeller; the impeller panel 38 is provided with an air inlet 33, the impeller back plate 37 is fixed by a rivet 35 and connected to the shaft seat 34, and the shaft seat 34 is connected with the fan shaft through the shaft hole 36; the casing 45 is provided with The air inlet 42 and the air outlet 47, the outline of the casing is an involute, the center of the involute circle coincides with the axis of the fan, the involute starts from the inside of the air outlet 47 of the casing, and the radius of the line gradually increases with the involute circle. Enlarged, until the outside of the casing air outlet 47 ends, the width B of the casing air outlet is equal to the circumference of the involute circle 43; The center coincides with the axis of the impeller.

The steam trap 8 is tangentially connected to the cyclone dust collector 1, and the cyclone dust collector 1 is spray-washed by steam condensed water with a higher temperature, so as to realize effective utilization of waste heat and waste water.

The dryer is provided with a feed hopper 13 and a discharge hopper to realize continuous feed drying.

The hollow anti-drop-shaped blade 31 is welded by two curved metals and has a symmetrical streamlined shape.

The casing 45 is fixed on the base 44 . The casing 45 acts as a seal, and the air inlet 42 obtains kinetic energy through the rotation of the impeller 41, and the energy is converted in the casing 45, and a part of the kinetic energy is converted into the static pressure energy of the gas, so that the output airflow has a velocity and a dynamic pressure head. There is a static pressure head, and the sum of the two is the total pressure of the fan.

The air inlet 42 of the casing can be connected to the air duct as required. The air inlet cover 46 is detachable and connected to the casing 45 by bolts. The volute-shaped involute profile of the casing 45 satisfies the airtightness of the fan casing and realizes energy delivery at the same time. The need for high-efficiency conversion enables the output airflow to reach the required flow and full pressure.

The casing air inlet cover plate 46 is fixedly connected to the casing 15 by bolts, and can be disassembled.

When the equipment is working, the steam plate 10 heats and dries the materials in a contact manner, generating more wet and hot steam, and the induced draft fan A tangentially introduces the wet and hot steam in the dryer between the tube-and-tube heat exchanger 4 and the cyclone dust collector 1 The cavity realizes the cyclone dust removal and performs the first step of cyclone heating on the fresh air entering the shell side of the heat exchanger, and the dust is output by the air locker 7.

The wet hot water vapor after dedusting enters the tube side of the heat exchanger 4 through the swirl riser tube 6, and finally is discharged from the exhaust pipe 3. The wet hot water vapor in the tube side heats the fresh air entering the shell side in the second step. After the two-step heating The fresh air is blown into the lower drying area by the blower 11 for gas replacement drying. The air flow in the lower drying area passes through the material from left to right, and the air flow turns back from the end of the middle partition 16, and then passes through the upper drying area from right to left. , so there is enough time and path for efficient drying of materials.

When the induced draft fan impeller of the present invention is used, because the blades are designed to be hollow and anti-waterdrop-shaped, and the blade shafts are radially and center-symmetrical, when rotating at high speed, the surface of the blades has a centrifugal self-cleaning effect under the centrifugal force, so that the dust cannot be attached due to the centrifugal force , so that it will not affect the dynamic and static balance of the impeller, and will not accumulate dust; the technical solution of this blade structure is especially suitable for the wide-impeller induced draft fan with large air flow.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Any person familiar with the art, without departing from the scope of the technical solution of the present invention, can use the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent implementation of equivalent changes example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims (6)

1. a tail heat recovery steam plate-press dryer, comprises drying machine and air-introduced machine, it is characterized in that; Drying machine is provided with driving wheel, follower and scraper flight animal material and carries on steam flat board, and steam flat board connects steam valve and drain valve; Median septum is had dry section to be divided into upper dry section and lower dry section in drying machine; Upper dry section tangentially connects the hot high-efficiency recoverer of cyclone dust removal tail be formed by stacking by tubular heat exchanger and cyclone dust collectors through air-introduced machine, dust is discharged at the cone end by wind stopping device after rotational flow dust-removing, tail gas connects cone by eddy flow tedge, through tubulation after being uniformly dispersed, being bored after bucket is concentrated by top and discharged by blast pipe; Tubular heat exchanger shell side upper end connects air inlet pipe, and lower end connects lower dry section through air blast; Described air-introduced machine comprises draught fan impeller and casing, and draught fan impeller comprises impeller backboard, impeller panel and blade, and blade arrangement becomes impeller Axial and radial, the anti-water-drop-shaped of centrosymmetric hollow; The anti-water-drop-shaped blade of hollow connects impeller panel and is welded to form impeller bodies with impeller backboard; Impeller panel is provided with air inlet, impeller backboard by the fixing also connection shaft seat of rivet, and axle bed is connected by axis hole and fan shaft; Casing is provided with air inlet and air outlet, cabinet form outline line is involute, the round heart of involute and blower fan axis coinciding, involute is from inside shell air outlet, line radius strengthens gradually with involute circle, terminate outside shell air outlet, shell air outlet width equals involute circumference; Shell air inlet is provided with cover plate, cover plate also has air inlet be convenient to connecting pipe, and axle center and impeller axis coinciding.

2. tail heat recovery steam plate-press dryer according to claim 1, is characterized in that: described drain valve tangentially connects cyclone dust collectors.

3. tail heat recovery steam plate-press dryer according to claim 1 or 2, is characterized in that: described drying machine is provided with feed hopper and discharge bucket, and the charging realizing serialization is dry.

4. tail heat recovery steam plate-press dryer according to claim 1 or 2, is characterized in that: the anti-water-drop-shaped blade of described hollow is synthesized by two panels Curved surface metal soldering group, and has symmetrical streamline profile.

5. tail heat recovery steam plate-press dryer according to claim 1 or 2, is characterized in that: described casing is fixed on support.

6. tail heat recovery steam plate-press dryer according to claim 1 or 2, is characterized in that: described shell air inlet cover plate is bolted to connection casing, and can dismantle.